We supply blasting grit trademarked KONTRASIL®. It’s a synthetic mineral blasting grit made of melted coal slag according to ISO 11126-4.

Chemical properties:


SiO248 - 54  Masse - %
Fe2O3 7 - 12  Masse - %
Al2O3 24 - 30  Masse - %
K2O 2 - 5  Masse - %
CaO 4 - 12  Masse - %

Technical data:

Mohs hardness:7
specific density:2.5 - 2.6 g/cm³
bulk density:1.3 g/cm³

Available sizes

all sizes in mm

Melted coal slag arises during the generation of electricity from coal. The liquid fire proof components of the coal are cooling down in a water bath. The solidified liquids are broken, dried and classified into several granulations.



  • no silicosis danger, because there is no free crystalline silica acid
  • no carcinogenic or toxic components
  • no water-soluble components
  • no waters or air pollution
  • no subsequent changes of the sand-blasting products


Application range:

  • Pretreating concrete surfaces before restoring
  • Derusting steel by means of compressed air jet technology
  • Surface preparation (removal of paint and rust)
  • Polishing, cleaning and grinding